Good point Don. Similarly, I noticed in the original post that, while the noise floor in the "fixed" case was flatter, it was also 10dB higher than the non-modified version, apparently masking the issue, not fixing it.
here is plot BEFORE "modification" (you can see terrible "spur" near 12kHz) http://forum.cqham.ru/download.php?id=32620 here is plots AFTER "modification": http://forum.cqham.ru/download.php?id=32621 Chad WE9V On Mon, Nov 24, 2008 at 3:47 PM, Don Wilhelm <[EMAIL PROTECTED]> wrote: > Alex, > > From what I see on your plots, the frequencies of the spurs have changed. > > On the BEFORE plot, I see a main signal at -9dB and the 2 major spurs are > -78 dB at 10.4 kHz and another at -77 dB at 12.6 kHz. The difference > between the main signal and the greatest spur is 68 dB. > > On the AFTER plot, I see the main signal at -27 dB, but there are 2 major > spurs - one at -85 dB at 5 kHz and another at -88 dB at 10.4 kHz. The > difference between the main signal and the greatest spur is now only 58 dB - > all in all a worsening of the signal to spur ratio. > > 73, > Don W3FPR > > Alexander Ponomarenko wrote: > >> Hi Eric, >> >> may be error in schematic, may be in my head. :) >> >> Please look on these new plots: >> >> here is plot with s9-level signal from XG1 BEFORE replaced W16: >> http://forum.cqham.ru/download.php?id=32057 >> >> and here is plot with s9-level signal from XG1 AFTER replaced W16: >> http://forum.cqham.ru/download.php?id=32650 >> >> Please, any yours comments. >> >> 73! >> Alex UR5LAM >> >> >> Eric Swartz - WA6HHQ, Elecraft wrote: >> >>> The schematic is in error. It was found that the coax was unnecessary. >>> >>> The levels of signals reported are not audible at greater than 50-60 dB >>> down from normal signals and do not impact our sensitivity spec. >>> >>> 73, Eric WA6HHQ >>> >> >> _______________________________________________ > Elecraft mailing list > Post to: Elecraft@mailman.qth.net > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com >
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